Col. Maxim Shapoval was driving a Mercedes Benz in Kiev when a bomb planted under the vehicle exploded, killing him instantly, according to Kiev police.

Two bystanders were also injured in the explosion.

The Ukrainian Defense Ministry said Shapoval was a part of the Chief Directorate of Intelligence, and Ukrainian media said he was chief of military intelligence’s special forces, according to the Associated Press.

Shapoval was reportedly investigating Russia’s military aggression in the ongoing war in the Donbass region for Ukraine’s case against Russia in the International Court of Justice, also known as The Hague, Lb.uasaid. Ukraine is currently suing Russia in the ICJ for “acts of terrorism and unlawful aggression.”